The present invention relates to a ringer device for a terminal unit such as a telephone set or a facsimile machine and, in particular, to an adaptive ringer device for allowing any desired ringer to be used in such terminal unit instead of the ringer originally supplied therewith.
A typical example of an adaptive ringer which can be used in conjunction with a conventional telephone set is an electric bell. Such electric bell is usually used when an indication of signal reception is required in addition to the ringing of the telephone set. The adaptive ringer is attached to a telephone, line and is actuated by a ringing signal on the line to ring in synchronism with an electric bell of the telephone set.
In the conventional adaptive ringer which has a similar construction to that of the telephone bell and is connected directly to a telephone line, the ringer and the telephone bell are actuated simultaneously. In order to prevent the ringing of the telephone bell, it is necessary to separate the telephone set from the telephone line and to connect it again to the line upon ringing of the adaptive ringer to initiate telephone communication. This procedure is troublesome. Further, there is a strong requirement for a ringer which produces not a bell sound but instead some audio sound such as a melody or voice. Such conventional adaptive ringer can not respond to such requirement.